private void RKstageImplicit(double PhysTime, double dt, double[][] k, int s, BlockMsrMatrix[] Mass, CoordinateVector u0, double ActualLevSetRelTime, double[] RK_as, double RelTime)
{
Debug.Assert(s < m_RKscheme.Stages);
Debug.Assert(m_RKscheme.c[s] > 0);
Debug.Assert(RK_as[s] != 0);
int Ndof = m_CurrentState.Count;
// =========
// RHS setup
// =========
m_ImplStParams = new ImplicitStage_AssiParams()
{
m_CurrentDt = dt,
m_CurrentPhystime = PhysTime,
m_IterationCounter = 0,
m_ActualLevSetRelTime = ActualLevSetRelTime,
m_RelTime = RelTime,
m_k = k,
m_u0 = u0,
m_Mass = Mass,
m_RK_as = RK_as,
m_s = s
};
// ================
// solve the system
// ================
NonlinearSolver nonlinSolver;
ISolverSmootherTemplate linearSolver;
GetSolver(out nonlinSolver, out linearSolver);
if (RequiresNonlinearSolver)
{
// Nonlinear Solver (Navier-Stokes)
// --------------------------------
nonlinSolver.SolverDriver(m_CurrentState, default(double[])); // Note: the RHS is passed as the affine part via 'this.SolverCallback'
}
else
{
// Linear Solver (Stokes)
// ----------------------
// build the saddle-point matrix
BlockMsrMatrix System, MaMa;
double[] RHS;
this.AssembleMatrixCallback(out System, out RHS, out MaMa, CurrentStateMapping.Fields.ToArray(), true);
RHS.ScaleV(-1);
// update the multigrid operator
MultigridOperator mgOperator = new MultigridOperator(this.MultigridBasis, CurrentStateMapping,
System, MaMa,
this.Config_MultigridOperator);
// init linear solver
linearSolver.Init(mgOperator);
// try to solve the saddle-point system.
mgOperator.UseSolver(linearSolver, m_CurrentState, RHS);
// 'revert' agglomeration
m_CurrentAgglomeration.Extrapolate(CurrentStateMapping);
}
// ================
// reset
// ================
m_ImplStParams = null;
}
